When you open a new tab in Firefox 13, you see a preview grid of most-visited web pages or something. Maybe. I’m not sure where that list comes from. Doesn’t matter, I don’t like it. There’s no way to disable it in the Firefox preferences, so you have to tweak the config settings to disable it.
I don’t know what the guys at Mozilla were thinking when they added this not-so-optional “feature”. Someone suggested they were trying to win… “The Most Retarded New Features Competition”. I would change that to “The Most Superfluous New Features Competition”.
To disable it:
1. Type about:config in the address bar.
2. Search for “browser.newtab.url”, and change the value to “about:blank”.